Enhanced Physiochemical and Mechanical Performance of Chitosan‐Grafted Graphene Oxide for Superior Osteoinductivity

Abstract

The regeneration of artificial bone substitutes is a potential strategy for repairing bone defects. However, the development of substitutes with appropriate osteoinductivity and physiochemical properties, such as water uptake and retention, mechanical properties, and biodegradation, remains challenging. Therefore, there is a motivation to develop new synthetic grafts that possess good biocompatibility, physiochemical properties, and osteoinductivity. Here, we fabricate a biocompatible scaffold through the covalent crosslinking of graphene oxide (GO) and carboxymethyl chitosan (CMC). The resulting GO‐CMC scaffold shows significant high water retention (44% water loss) compared with unmodified CMC scaffolds (120% water loss) due to a steric hindrance effect. The modulus and hardness of the GO‐CMC scaffold are 2.75‐ and 3.51‐fold higher, respectively, than those of the CMC scaffold. Furthermore, the osteoinductivity of the GO‐CMC scaffold is enhanced due to the π–π stacking interactions of the GO sheets, which result in striking upregulation of osteogenesis‐related genes, including osteopontin, bone sialoprotein, osterix, osteocalcin, and alkaline phosphatase. Finally, the GO‐CMC scaffold exhibits excellent reparative effects in repairing rat calvarial defects via the synergistic effects of GO and bone morphogenetic protein‐2. This study provides new insights for developing bone substitutes for tissue engineering and regenerative medicine.

Two-dimensional nanomaterials: fascinating materials in biomedical field

“…As one of the most typical 2D nanomaterials, GO has been selected to develop tissue engineering. For instance, Ruan et al [80] constructed GO-based biocompatible scaffolds by covalent cross-linking GO with carboxymethyl chitosan (CMC). The resulting porous GO-CMC scaffolds showed significantly higher modulus and hardness compared with CMC scaffolds.…”

Bioinspired Collagen Scaffolds in Cranial Bone Regeneration: From Bedside to Bench

“…Various other materials that are not naturally found in bone, such as graphene oxide-based composites, were also not examined in this review but may be of potential future interest in bone regeneration. [140] The sheer numbers and combinations of collagen-based scaffolds, even within relatively narrow confines, suggest that a more directed method should be considered with optimization at every step of the fabrication process. That is, we should optimize from the best material or materials reported, rather than to work from materials that have been demonstrated to yield suboptimal results for the same application.…”

Enhanced bioactivity and osteoinductivity of carboxymethyl chitosan/nanohydroxyapatite/graphene oxide nanocomposites

“…[7][8][9][10][11][12][13] A number of studies have shown that carbon nanotubes, graphene nanomaterials and silicon nanomaterials can signicantly manipulate osteoblast adhesion and differentiation and promote bone formation via chemical inducing effects. [14][15][16][17][18][19] Although nanomaterials can signicantly improve scaffold bioactivity, the limited incorporation of nanomaterials into a scaffold is necessary when considering the biosafety in vivo, [20][21][22][23] and the bioactivity of nanocomposite scaffolds continues to be explored within the biosafety dose of the nanomaterials.…”